Estrogen metabolism and the musculoskeletal system

Clinical strategies to support hormone balance and structural integrity

Most clinicians recognize estrogen for its role as a sex hormone, but fewer appreciate its profound influence on structural health. Estrogen supports musculoskeletal integrity by promoting muscle growth and repair, enhancing bone density and stimulating collagen production. However, estrogen can also contribute to inflammation, increased injury risk and pain. Estrogen metabolism is pivotal in determining whether it acts as a protective hormone or fuels musculoskeletal dysfunction.

Estrogen’s role in musculoskeletal health

Estrogen exerts its effects on the musculoskeletal system through direct interactions with estrogen receptors within bones, muscles, ligaments, tendons, cartilage and fascia. It stimulates osteoblast activity and suppresses osteoclast function, helping maintain bone density and preventing osteoporosis. In muscle tissue, estrogen enhances glucose uptake, supports mitochondrial efficiency and promotes muscle fiber regeneration and growth. Estrogen also enhances the collagen content of connective tissue.

Dysregulated estrogen metabolism

While estrogen is critical for physical stability and healing, estrogen level imbalances and dysregulated estrogen metabolism can degrade musculoskeletal integrity. Estrogen “dominance,” characterized by disproportionate estrogen activity relative to progesterone and the presence of less favorable, more inflammatory estrogen metabolites, may manifest clinically through joint hypermobility, recurrent ligamentous injuries, delayed healing and chronic inflammation. Conditions such as fibromyalgia and temporomandibular joint dysfunction can also reflect estrogen imbalance and problems with estrogen metabolism.

The process of estrogen metabolism

The liver is the primary site of estrogen metabolism. During Phase I, estrogen undergoes hydroxylation through the action of cytochrome P450 enzymes. Three primary metabolites provide essential health benefits but can also promote disease and dysfunction when out of balance. These metabolites include 2-hydroxyestrone (2-OH-E1), the least estrogenic of the three, which provides protective antioxidant and anti-inflammatory effects. The most estrogenic metabolite, 16-hydroxyestrone (16-OH-E1), can contribute to increased cellular proliferation and inflammation. 4-hydroxyestrone (4-OH-E1) is less estrogenic than 16-OH-E1, but is also considered a less favorable metabolite because it can promote DNA damage and carcinogenesis in certain situations. While the typical breakdown of estrogen is expected to produce some amount of all three metabolites, a favorable estrogen metabolism pathway emphasizes higher levels of the 2-OH-E1 metabolite relative to 16-OH-E1 metabolite levels.

During Phase II of estrogen metabolism, estrogen metabolites undergo conjugation, becoming water-soluble and primed for elimination. Nutrients such as B vitamins, magnesium, sulfur compounds and methyl donors are critical in these detoxification pathways.

In Phase III, the estrobolome—the collection of gut bacteria involved in metabolizing estrogen—plays a key role in regulating estrogen clearance. Specific gut bacteria secrete beta-glucuronidase enzymes capable of deconjugating estrogen, allowing its reabsorption and potentially promoting systemic estrogen dominance. Proper balance and diversity within the gut microbiota thus significantly impact estrogen metabolism efficiency and overall musculoskeletal health. Estrogens not reabsorbed are eliminated via the urine, bile and stool.

Patient risk factors

When assessing patients for concerns related to the impact of estrogen on musculoskeletal health, DCs should be alert to specific patient characteristics and risk factors. Patients most likely to exhibit estrogen-related musculoskeletal issues include women in perimenopause or post-menopause and those experiencing irregular menstrual cycles, which can reflect ovulatory dysfunction. For example, patients with polycystic ovary syndrome—the most common endocrine disorder in women—often exhibit irregular menstrual cycles and relative estrogen dominance. Signs and symptoms of high 16-OH-E1 levels relative to 2-OH-E1 include premenstrual syndrome, heavy menses, uterine fibroids, abdominal obesity and fibrocystic breast changes. The presence of fatty liver disease or GI dysfunction should alert the clinician that estrogen metabolism may be suboptimal.

Supportive lifestyle and dietary practices

Nutrition and lifestyle practices can support proper estrogen metabolism by optimizing detoxification pathways and liver health, as well as by supporting digestive processes and a healthy gut microbiome.

• Regular exercise: Encourage patients to engage in 150 minutes of moderate to vigorous physical activity weekly. Regular exercise positively shifts estrogen metabolism toward the favorable 2-OH-E1 metabolite, relative to the 16-OH-E1 metabolite. Exercise supports bone density, muscle growth, joint stability and connective tissue integrity.
• Reduce exposure to xenoestrogens: Educate patients about avoiding synthetic estrogen-mimicking compounds in personal care products, plastics, pesticides, thermal paper receipts and ultra-processed foods. Endocrine-disrupting compounds like bisphenol-A and parabens bind to estrogen receptors, disrupt hormone systems and increase signs and symptoms of estrogen dominance.
• Dietary fiber: Patients should aim for 25-35 grams of dietary fiber daily, including insoluble, soluble and prebiotic fiber types. Whole-food fiber from foods like fruits, vegetables, whole grains and seeds enhances gut microbial diversity and optimizes estrogen elimination through stool, minimizing reabsorption of harmful metabolites.
• Probiotics: Recommend probiotics and foods rich in beneficial bacteria, such as yogurt or fermented vegetables. A healthy, diverse microbiome supports effective estrogen metabolism, reduces inflammatory cytokine release and improves overall detoxification processes.
• Cruciferous vegetables: Encourage daily intake of cruciferous vegetables, such as Spanish black radish, kale and Brussels sprouts. These vegetables contain glucobrassicin that is converted into indole-3-carbinol (I3C) and diindolylmethane (DIM), potent compounds promoting the protective 2-OH-E1 estrogen metabolism pathway.
• Ground flaxseed: Flaxseed is high in lignans, plant-derived estrogens that weakly bind estrogen receptors and protect against more potent estrogen activity. Regular ground flaxseed consumption supports the production of the 2-OH-E1 estrogen metabolite and reduces potential inflammatory effects from excessive estrogen stimulation. Ground flaxseed should be stored in the freezer to slow the oxidation of fatty acids.
• Turmeric: Curcuminoids and other bioactive compounds found in turmeric fight inflammation and can promote favorable estrogen metabolite levels by upregulating key metabolic pathways. Because the bioavailability of curcumin is limited, consider supplementation that uses galactomannan, a type of fiber from fenugreek seeds that can significantly increase the bioavailability of curcuminoids. 

Jessica Stefanski, NMD, LAC, FABNE, is the clinical education manager at Standard Process. She is a licensed naturopathic physician and licensed acupuncturist with 15 years of clinical experience focused primarily on women’s health and endocrinology. She obtained her doctorate and master’s degrees at the National University of Natural Medicine in Portland, Oregon.